Bottle base



FIG. 1 is a bottom, side isometric view of a bottle base showing my new design;

FIG. 2 is a side elevational view thereof;

FIG. 3 is another side elevational view thereof;

FIG. 4 is a bottom plan view thereof; and,

FIG. 5 is an enlarged vertical cross sectional view taken along line 5—5 of FIG. 3.

The broken line showing of a bottle is included for the purpose of illustrating only and forms no part of the claimed design. 

The ornamental design for a bottle base, as shown and described. 